Efficacy of Oral Vitamin D Supplementation in Reducing Body Mass Index and Lipid Profile in Adolescents and Young Adults in Colombia: a Pilot Clinical Trial Protocol Nested in the SIMBA Cohort
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 发起方
- 入组人数
- 150
- 试验地点
- 2
- 主要终点
- Change in lipid profile (Total cholesterol, low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglycerides) between baseline and week 15
研究概览
简要总结
This study assesses whether oral supplementation with vitamin D contributes to the reduction of body mass index and lipid profile in adolescents and young adults. The intervention group will receive 1000 IU of vitamin D (DV) and the control group 200 IU of DV.
详细描述
Sample size: the simple size was calculated considering the following parameters: an expected difference in the study outcomes (overweight, obesity, and alteration of the lipid profile) of 20% between the intervention group and the control group; a power of 90%, an alfa of 5%, an intervention group/control group ratio of 1:1, and a 20% adjustment for losses to follow-up, resulting in a sample of 270 participants (n=135 intervention and n=135 control group). The OpenEpi software was used for the calculation. Since this is a pilot study and considering the feasibility, the research team decided on a sample size of 150 participants (n=75 intervention group and n=75 control group).
Randomization and blinding: the randomization process will take place in two stages. An engineer from the data central will conduct the randomization of the list of the 217 potentially eligible participants by means of a computer program with random numbers and it will select 150 individuals to participate in the study. Subsequently, a nurse will make phone calls to schedule appointments and formalize the participation in the study, the signature of the informed consent, and the taking of baseline measures. Once these stages are concluded, the assignment of treatment in real time will be made with the support of a computer program. The procedure will take place by means of a single assignment sequence that determines the assignment code for each participant's treatment.
Supplements will be packaged in individual packages with the total number of doses per participant (105 doses). The coding of the packages will be in charge of the laboratory in charge of providing the supplements, which in turn will send to the designated person at the data center by institutional e-mail, a document with the list of codes and the dose of the supplement. The 1000 IU and 200 IU doses of VD will be provided in white containers and will be identical in terms of physical and organoleptic characteristics, to ensure that both participants and investigators are blinded to the treatment. To maximize adherence to the intervention, participants will be required to cross out daily supplementation on a calendar with the study period, which participants should return at the end of the study.
The results of the assignment will only be known by the systems engineer at the data center. In other words, this information "will not be visible" to the coordinating nurse, laboratory personnel in charge of processing biological samples, pediatrician, principal investigator of the study, or the epidemiologist in charge of quality control and data analysis. This will ensure the masking of the people in charge of measuring the outcomes, administering the intervention and analyzing the study data.
Recruitment: for recruitment, a study nurse in charge of enrollment will contact by phone the 217 successful participants of the third re-contact, explain the objective of the study and inquire about the interest to participate; if there is a positive response, inclusion and exclusion criteria will be verified. A list of eligible participants will be generated from the above process and sent to the person in charge of the randomization process.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Treatment
- 盲法
- Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
盲法说明
The assignment of treatment in real time will be made with the support of a computer program. The procedure will take place by means of a single assignment sequence that determines the assignment code for each participant's treatment. This process allows all participants in the study to be assigned to any of the treatment groups.
Supplements will be packaged in individual packages with the total number of doses per participant (105 doses). The coding of the packages will be in charge of the laboratory in charge of providing the supplements, which in turn will send to the designated person at the data center by institutional e-mail, a document with the list of codes and the dose of the supplement.
The 1000 IU and 200 IU doses of VD will be provided in white containers and will be identical in terms of physical and organoleptic characteristics, to ensure that both participants and investigators are blinded to the treatment.
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Belonging to the SIMBA cohort.
- •Age ≥ 18 years.
- •Re-contact consent from previous studies.
排除标准
- •Medical diagnosis of diabetes mellitus, clinically manifest endocrinopathies, acute or chronic infectious liver disease, and kidney disease.
- •Adolescents or Young adults subject to treatment with steroids or hormones (except levothyroxine) up to one month before lab sample taking.
- •Current supplementation with VD (any form).
结局指标
主要结局
Change in lipid profile (Total cholesterol, low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglycerides) between baseline and week 15
时间窗: Baseline and week 15
Serum is measured from the same blood samples drawn for vitamin D levels. The processing and analysis of the samples will be done respectively through enzymatic technique, selective liquid detergent, selective detergent accelerator and Glycerol Phosphate Oxidase.
Change in body mass index between baseline and week 15
时间窗: Baseline and week 15
Change in body mass index (BMI) will be made through of the measure of body weight will be in kilograms (kg) to one decimal place, and the size in meters (m) to two decimal places. From these measurements the body mass index will be obtained using the formula: BMI = Weight (kg) / size (m)2.
Change in 25-hydroxyvitamin D [25(OH)D] levels between baseline and week 15
时间窗: baseline and week 15
After a 10-12 hour fast, in peripheral venous blood 25-hydroxyvitamin D \[25(OH)D\] is quantified in serum by chemiluminescent microparticle immunoassay (CMIA).
次要结局
- Change in fasting blood glucose level between baseline and week 15(Baseline and week 15)
- Change in waist - hip ratio between baseline and week 15(Baseline and week 15)
- Change of percentage body fat (PBF) in skin folds between baseline and week 15(Baseline and week 15)